BACKGROUND Limited information is available regarding genetic contributions to valvular calcification, which is an important precursor of clinical valve disease. METHODS We determined genomewide associations with the presence of aorticvalve calcification (among 6942 participants) and mitral annular calcification (among 3795 participants), as detected by computed tomographic (CT) scanning; the study population for this analysis included persons of white European ancestry from three cohorts participating in the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium (discovery population). Findings were replicated in independent cohorts of persons with either CT-detected valvular calcification or clinical aortic stenosis. RESULTS One SNP in the lipoprotein(a) (LPA) locus (rs10455872) reached genomewide significance for the presence of aorticvalve calcification (odds ratio per allele, 2.05; P = 9.0×10−10), a finding that was replicated in additional white European, African-American, and Hispanic-American cohorts (P<0.05 for all comparisons). Genetically determined Lp(a) levels, as predicted by LPA genotype, were also associated with aorticvalve calcification, supporting a causal role for Lp(a). In prospective analyses, LPA genotype was associated with incident aortic stenosis (hazard ratio per allele, 1.68; 95% confidence interval [CI], 1.32 to 2.15) and aortic-valve replacement (hazard ratio, 1.54; 95% CI, 1.05 to 2.27) in a large Swedish cohort; the association with incident aortic stenosis was also replicated in an independent Danish cohort. Two SNPs (rs17659543 and rs13415097) near the proinflammatory gene IL1F9 achieved genomewide significance for mitral annular calcification (P = 1.5×10−8 and P = 1.8×10−8, respectively), but the findings were not replicated consistently. CONCLUSIONS Genetic variation in the LPA locus, mediated by Lp(a) levels, is associated with aorticvalve calcification across multiple ethnic groups and with incident clinical aortic stenosis. (Funded by the National Heart, Lung, and Blood Institute and others.)

Aortic calcification is an important independent predictor of future cardiovascular events. We performed a genome-wide association meta-analysis to determine single nucleotide polymorphisms (SNPs) associated with the extent of abdominal (AAC, n = 9,417) or descending thoracic (TAC, n = 8,422) aortic calcification. Two genetic loci, HDAC9 and RAP1GAP, were associated with AAC at a genome-wide level (P < 5.0 × 10 −8). No SNPs were associated with TAC at the genome-wide threshold. Increased expression of HDAC9 in human aortic smooth muscle cells (HASMCs) promoted calcification and reduced contractility, while inhibition of HDAC9 in HASMCs inhibited calcification and enhanced cell contractility. In matrix Gla protein (MGP)deficient mice, a model of human vascular calcification, mice lacking HDAC9 had a 40% reduction in aortic calcification and improved survival. This translational genomic study identifies the first genetic risk locus associated with calcification of the abdominal aorta and describes a novel role for HDAC9 in the development of vascular calcification.

SUMMARYMeasurement of the inflammatory biomarker high sensitivity C-reaction protein (hsCRP) has been proposed for assessment of risk for cardiovascular disease (CVD). It remains unclear which patient populations would benefit from and should be targeted for hsCRP testing. Current data indicate that hsCRP levels are independently associated with risk of CVD, including both coronary events and stroke, in various asymptomatic populations; add predictive power to current coronary risk scores for some intermediate risk individuals; and are associated with clinical outcomes in high risk individuals treated with statin therapy. HsCRP levels are also associated with incident diabetes and CVD outcomes in patients with the metabolic syndrome. There is a growing body of evidence to support recommendations for measurement of hsCRP in selected asymptomatic individuals deemed to be at intermediate risk of CVD according to traditional risk factor assessment and who do not already warrant treatment with chronic aspirin and statin therapy, and selected secondary CVD prevention patients for further risk stratification in combination with LDL cholesterol. [Aus: to appear online: Dr. Musunuru has served as a consultant for Alnylam Pharmaceuticals within the last year. Dr. Gluckman has received honoraria from Sanofi-Aventis and Pfizer and has served as a consultant for Merck within the last year. Dr. Davidson has received honoraria from and served as a consultant for diaDexus within the last year. We declare no conflicts of interest pertaining to this topic.]REVIEW CRITERIA We performed a comprehensive review of peer-reviewed publications that were identified through searches of MEDLINE and the Cochrane Database from January 1990 through December 2007 using the search term "C-reactive protein", in combination with one of the following: "heart disease", "stroke", "hypertension", "metabolic syndrome" and "stroke". Bibliographies from these references were also reviewed, and additional studies were identified by experts. Initially identified papers were English language, with the subject of the paper being the clinical risk prediction of cardiovascular disease or diabetes mellitus. All studies were considered in our analysis. In analyzing the association of C-reactive protein (whether high-sensitivity or not) with cardiovascular disease (coronary heart disease or stroke) or diabetes in asymptomatic populations, we selected studies that used multivariate adjustment for at least four traditional cardiovascular disease or diabetes risk factors. We excluded studies in which the populations had significant prevalence of comorbidities (>10% with, e.g., systolic heart failure, diabetes). In studies that included both men and women, when separate data were available for each sex we considered them separately rather than as a single population. When multiple publications reporting data from the same cohort were available, we chose the most recent publication.

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